Risk of Hypertrophic Scars from Earlobe Surgery?

Hypertrophic scarring (thick wide scar) is different from keloids (scar mass that keeps growing well outside the boundaries of the scar).  If you have not had keloids develop in the ear area before from previous piercings, then it is unlikely that you would develop keloid in your ear now.

Earlobe surgery is performed under sterile conditions with minimal tension applied to the repair.  Although a hypertrophic scar is possible, it is not common.  Thick scars associated with the earlobes should be managed early and aggressively.  If you are worried about the possibility of hypertrophic or keloid scarring, seek a surgeon who is familiar with earlobe repair and scar revision. 

It is possible to develop keloid on your earlobes after reduction or repair; however it is not inevitable. Should you start seeing keloids develop, the key is to start treatment early. Steroid injections, pressure therapy and even radiation therapy can all be effective.

I have repaired hundreds of torn earlobes and have yet to see a keloid or hypertropic scar.  I'm not certain why this is because I have seen many keloids (almost always in black patients) as a result of ear piercing.  In correcting those problems, occasional recurrences are observed. 

Torn earlobes are quite common in longstanding piercings, especially in patients who prefer long/ heavy earrings. In my practice, I see this problem quite commonly and have yet to see a keloid form after repair. However, avoiding the problem is largely related to patient selection. The three most common sites for keloid formation are the sternum (chest), deltoid, and earlobe. Keloid formation has a genetic predisposition, generally occurring in darker skinned patients. The one factor that goes against keloid formation in your circumstance is a prior piercing with no history of keloid in that ear.

There is a significant differerence between hypertrophic and keloid scars. The former is more likely what you have on your shoulder.
If you have had your ears pierced in the past, that would be a better indication of your tendency to develop hypertrophic or keloid scars.

It is always a a possibility to develop a keloid or hypertrophic scar on the ear lobe incision.
The fact that you have a hypertrophic scar on the shoulder is an indication that you are at risk of developing abnormal scar in the earlobe incision.
If you have a scar anywhere else on the body and has healed well then you are probably ok to have earlobe surgery. Shoulders are high stress areas and can easily develop hypertrophic scars.
Regards

Plastic surgeons are often called upon to fix torn earlobes. This seems to be especially true in Las Vegas, where big, dangling earrings are in style. Often a child will grab them, or they will get caught on something and rip. Sometimes it is just time that makes a larger hole in the earlobe.
Hypertrophic scarring can occur anywhere. Hispanic, Asian, and Dark European, (e.g. Italian) patients are more at risk. Keloid scarring can also occur anywhere, and with this type of scarring the scar goes over the boundaries of the incision. Keloid scaring is more common in Black patients.
Careful planing and aftercare with compression earrings, wearing surgical tape to decrease tension on the wound, and wound healing salves all can help decrease the chance of unwanted scarring. Treatment of the scar with injections of steroids can also decrease the size of the scar.
Scar revision 10 to 12 months after surgery is a possibility. There is always a possibility that the scar could be worse than the current scar.
Best thing is to have a good conversation with your board certified plastic surgeon to see about your individual situation.

The shoulder is one of the worst areas of the body in terms of scarring; I would not extrapolate a poor shoulder scar to conclude that you will automatically scar badly on the earlobe.  Keloid formation is a different process from scar hypertrophy.  If you did not form keloids from the ear piercing or laceration, it is highly unlikely that you will form a keloid mass at the site of earlobe repair.  In terms of scar hypertrophy, this can be controlled by kenalog injection should it develop  but is uncommon in the earlobe.

If you have earlobe piercings and do not have any hypertrophic scarring or keloids from that, there would seem to be a lower likelihood that you would form keloids after repair of your earlobes. However, you have a hypertrophic scar or keloid on your shoulder so that would suggest a propensity to forming hypertrophic scars or keloids. I have seen a number of keloids on the earlobes of people. Most of these are African-Americans, and most of these patients also had keloids on the jawline or chest or back or shoulders. The problem with keloids is that you cannot predict that a keloid will develop, and once you develop a keloid, you have to be very careful with further surgery to that keloid for fear of making it worse. Most of these people that I have seen with keloids on their ears developed keloids after ear piercing so the fact that you have piercings and no keloids would suggest that your likelihood of developing keloids is less. But unfortunately, there can't be any guarantees. Best to meet with a dermatologist to evaluate the scarring on your shoulder and discuss your options for your earlobes.